#include<iostream>
#include<cstring>
#include<vector>
#include<map>
#include<cstdio>
#include<algorithm>
#include<string>
#include<string.h>
#include<queue>
#include<math.h>
#include<set>
#include<functional>
using namespace std;
using ull = unsigned long long;
#define int long long
//using i128 = __int128_t;
inline int inc(int x, int v, int mod) { x += v;return x >= mod ? x - mod : x; }//代替取模+
#define endl '\n'
typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PII;

const int N = 2e3 + 10, M = 1e5 + 10;

inline int read()
{
    int x = 0, f = 1;
    char ch = getchar();
    while (ch < '0' || ch > '9')
    {
        if (ch == '-')
            f = -1;
        ch = getchar();
    }
    while (ch >= '0' && ch <= '9')
        x = x * 10 + ch - '0', ch = getchar();
    return x * f;
}


void solve()
{
    int n,m;
    cin >> n >> m;

    vector<vector<int>> a(n + 1,vector<int>(m + 1));

    for(int i = 1; i <= n; i ++)
    {
        for(int j = 1; j <= m; j ++)
        {
            cin >> a[i][j];
        }
    }
    map<int,int>mp1;
    map<int,int>mp2;

    for(int i = 1; i <= n; i ++)
    {
        for(int j = 1; j <= m; j ++)
        {
            mp1[i + j] += a[i][j];
            mp2[i - j] += a[i][j];
        }
    }
    int ans = 0;

    for(int i = 1; i <= n; i ++)
    {
        for(int j = 1; j <= m; j ++)
        {
            int t = mp1[i + j] + mp2[i - j] - a[i][j];
            ans = max(ans,t);
        }
    }
    cout << ans << endl;
}
signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    int tt;
    tt = 1;
    cin >> tt;
    while (tt--)
    {
        solve();
    }
}